近日，美国哥伦比亚大学的Cory R. Dean及其研究团队取得一项新进展。经过不懈努力，他们揭示5.0°扭曲双分子层WSe₂的超导性。相关研究成果已于2025年1月22日在国际权威学术期刊《自然》上发表。

本文报道了在5.0°扭曲双层WSe₂中观察到超导电性，其最高临界温度达到426毫开尔文。超导态出现在位移场和密度的有限区域内，该区域毗邻一个金属态，该金属态的费米面重构被认为源于反铁磁（AFM）序。在低温下，观察到超导相和磁相之间存在清晰的边界，这让人联想到自旋涨落介导的超导电性。这项研究结果表明，莫尔平带超导电性不仅局限于石墨烯结构。二维过渡金属硫化物（TMDs）中一些石墨烯所不具备但TMDs本身固有的材料特性，如本征带隙、强自旋-轨道耦合、自旋-谷锁定和磁性，为探索比仅含石墨烯的结构更广泛的超导参数空间提供了可能。

据悉，扭曲双层和三层石墨烯中超导电性的发现引起了极大兴趣。这些系统的关键特征是层间耦合与莫尔超晶格的相互作用，这种作用产生了具有强关联性的低能平带。在其他二维材料（如过渡金属硫化物（TMDs））的晶格失配和/或扭曲异质结构中，莫尔条纹也可以诱导出平带。尽管在莫尔TMDs中确实观察到了多种关联现象，但超导电性的确凿证据至今尚未出现。

附：英文原文

Title: Superconductivity in 5.0° twisted bilayer WSe₂

Author: Guo, Yinjie, Pack, Jordan, Swann, Joshua, Holtzman, Luke, Cothrine, Matthew, Watanabe, Kenji, Taniguchi, Takashi, Mandrus, David G., Barmak, Katayun, Hone, James, Millis, Andrew J., Pasupathy, Abhay, Dean, Cory R.

Issue&Volume: 2025-01-22

Abstract: The discovery of superconductivity in twisted bilayer and trilayer graphene has generated tremendous interest. The key feature of these systems is an interplay between interlayer coupling and a moiré superlattice that gives rise to low-energy flat bands with strong correlations. Flat bands can also be induced by moiré patterns in lattice-mismatched and/or twisted heterostructures of other two-dimensional materials, such as transition metal dichalcogenides (TMDs). Although a wide range of correlated phenomena have indeed been observed in moiré TMDs, robust demonstration of superconductivity has remained absent. Here we report superconductivity in 5.0° twisted bilayer WSe₂ with a maximum critical temperature of 426mK. The superconducting state appears in a limited region of displacement field and density that is adjacent to a metallic state with a Fermi surface reconstruction believed to arise from AFM order. A sharp boundary is observed between the superconducting and magnetic phases at low temperature, reminiscent of spin fluctuation-mediated superconductivity. Our results establish that moiré flat-band superconductivity extends beyond graphene structures. Material properties that are absent in graphene but intrinsic among TMDs, such as a native band gap, large spin–orbit coupling, spin-valley locking and magnetism, offer the possibility of accessing a broader superconducting parameter space than graphene-only structures.

DOI: 10.1038/s41586-024-08381-1

Source: https://www.nature.com/articles/s41586-024-08381-1